Floral design 70 #2520
 Dark  CC 0

Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.

Source Firkin

 More Textures
Background pattern purple #1946
 Colorful  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Seamless Core Pattern 10 #171
 Dark  CC 0

Seamless Core Pattern 10

Source GDJ

Prismatic Abstract Geometric Background #269
 Noise  CC 0

Prismatic Abstract Geometric Background derived from an image on Pixabay.

Source GDJ

Dark Blue Gray Wallpaper Texture #901
 Stripes  CC BY-SA 3.0

This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!

Source V. Hartikainen

Background pattern 224 (colour 5) #2338
 Colorful  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Background pattern 117@2X #525
 Noise  CC 0

A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.

Source Firkin

Pattern generator #161
 Noise  CC 0

A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.

Source Lazur URH

Cross Stripes #47
 Dark  CC BY-SA 3.0

Nice and simple crossed lines in dark gray tones.

Source Stefan Aleksić

Prismatic Triangular Seamless Pattern III With Background #273
 Dark  CC 0

Prismatic Triangular Seamless Pattern III With Background

Source GDJ